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A graphing calculator is recommended.Solve the given equation or inequality graphically. State your answers rounded to two decimals.(a) 5x2 − x3 = −x2 + 3x + 4 (Enter your answers as a comma-separated list.)x = (b) 5x2 − x3 ≤ −x2 + 3x + 4 (Enter your answer using interval notation.)x =

User Navakanth
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1 Answer

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a) Given the equation


5x^2-x^3=-x^2+3x+4

First, simplify the equation


\begin{gathered} 5x^2-x^3+x^2=-x^2+3x+4+x^2 \\ 6x^2-x^3=3x+4 \\ 6x^2-x^3-3x=3x+4-3x \\ 6x^2-x^3-3x=4 \\ 6x^2-x^3-3x-4=4-4 \\ 6x^2-x^3-3x-4=0 \\ \operatorname{Re}-\text{order} \\ -x^3+6x^2-3x-4=0 \end{gathered}

Then we graph the equation

The solutions are the values of x for which y = 0. These are:


\begin{gathered} x=-0.58 \\ x=1.29 \\ x=5.29 \end{gathered}

Answer a: x = -0.58, 1.29, 5.29

b) Given the inequality


5x^2-x^3\leq-x^2+3x+4

Solve for x using the graph

So, the solution is:


\begin{gathered} -0.58\leq x\leq1.29 \\ or \\ x\ge5.29 \end{gathered}

In interval notation:


\lbrack-0.58,1.29\rbrack\cup\lbrack5.29,\infty)

Answer b:


\lbrack-0.58,1.29\rbrack\cup\lbrack5.29,\infty)

A graphing calculator is recommended.Solve the given equation or inequality graphically-example-1
A graphing calculator is recommended.Solve the given equation or inequality graphically-example-2
User Ionpoint
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